Added domain lock list to force domains not in the list to load in Mobile Safari

Specify a comma-separated list of URL prefixes, like @"http://seculartotem.com,http://jetpack.wordpress.com" and all non-matches will be opened in Mobile Safari
Added NSString currentURL property which returns the current URL a user navigated to using a touch event
Merge pull request #16 from argentini/master

Added domain lock list to force domains not in the list to load in Mobile Safari